link hexcvt

procedure main()
write("text    = ",image(u := "http://foo bar/"))
write("encoded = ",image(ue := encodeURL(u)))
end

procedure encodeURL(s)           #: encode data for inclusion in a URL/URI
static en
initial {                           # build lookup table for everything
   en := table()
   every en[c := !string(~(&digits++&letters))] := "%"||hexstring(ord(c),2)
   every /en[c := !string(&cset)] := c
   }

every (c := "") ||:= en[!s]         # re-encode everything
return c
end